The Real Reason Hydrogen Fuel Isn't More Popular

Talia Roepel
Mon, October 5, 2026 at 1:05 PM MDT
BGR


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Key takeaways

Hydrogen is being considered as a promising clean fuel for the future due to its abundance and ability to emit only water when burned.

In the effort to reduce climate change and eliminate the abundance of fossil fuels, one particular element has been identified as so promising that it could be the future of clean fuels. That element is hydrogen. Earth has a massive supply of hydrogen. It can be burned in the same way we use oil or gas, but instead of polluting the air, it only emits water. So if there is plenty of it and it's so clean, why isn't it more popular?

There's no chemical element more abundant than hydrogen in the universe, but it's still difficult to obtain in a pure and ready-to-use form. To use it in the same way we use oil and gas, we must manufacture it. The problem is that the manufacturing process itself usually releases significant climate-warming emissions. There is little point in using clean hydrogen energy if the process to create it negates its benefits.

Read more: What's Happening To Earth Right Now Can't Be Explained By Climate Models
The problems with manufacturing hydrogen

Data from the International Energy Agency (IEA), shows that 96% of hydrogen fuel production around the world uses fossil fuels — releasing at least nine tons of carbon dioxide (CO₂) per ton of hydrogen, and even up to twelve tons. The various production processes used impact the levels of CO₂ emitted.

Most of the hydrogen used today — including around 95% of projects in the U.S. — is known as gray hydrogen; made by breaking down natural gas using high heat. While this process does produce hydrogen, it also releases about 12 kilograms of CO₂ for every single kilogram of hydrogen. A cleaner option is blue hydrogen, which uses the same method but adds carbon capture technology to trap some of the emissions. Even then, it still releases three to five kilograms of CO₂ per kilogram of hydrogen.

As part of a team researching new ways of creating hydrogen, without direct CO₂ emissions, Professor Graham Hutchings of Cardiff University stated, "Finding sustainable ways of creating the products we need for everyday life and to meet net zero ambitions for the future is a key challenge facing the chemical industry. Hydrogen is widely regarded as one way of achieving these ambitions because it is made from natural gas. However, it is extremely energy intensive and, of course, when created through traditional methods, it produces large amounts of carbon dioxide limiting its environmental benefits."
Research into cleaner ways to produce hydrogen

JHVEPhoto/Shutterstock

One potential process which would be safer for our climate, is an option referred to as green hydrogen. This utilizes clean and renewable energy, like wind or solar power, to manufacture the hydrogen. The process can emit one kilogram or less of harmful emissions, which is significantly less than the current processes in place for gray and blue hydrogen.

Researching the concept at the Massachusetts Institute of Technology (MIT) Energy Initiative, a key stumbling block is the cost of the electrolyzers that are used to split the hydrogen from water. Furthermore, wind and solar power aren't reliable enough for a continuous manufacturing process. That leaves the options of either stopping production when conditions are not ideal, or having to rely on more traditional methods of producing hydrogen, which is counterintuitive.

Principal research scientist at the MIT Energy Initiative, Emre Gençer, explained, "If we get cheaper electrolyzers, you will definitely see more green hydrogen coming online ... The reason we are talking about hydrogen today [is] because there are hard to abate sectors with electrification or other decarbonization options, and that's why we see hydrogen as a solution. But that completely depends on how clean our hydrogen production is."

Read the original article on BGR.

 

Rock weathering tells a new story: more erosion does not always mean more carbon consumption

A study of the Lancang River shows that silicate, carbonate, and sulfide weathering respond differently to erosion

Science China Press

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All data are corrected for runoff using θsil = 0 and θsulf,carb = −0.75. Green indicates carbonate, yellow indicates silicate, and blue indicates sulfide. The dashed lines represent power-law fits to erosion sensitivity. Sites with strong secondary carbonate precipitation were excluded from the fitting. Data from other study areas are reported in Bufe et al. (2024).

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Credit: ©Science China Press

The uplift-weathering hypothesis suggests that tectonic uplift increases erosion, exposes fresh silicate minerals, and accelerates reactions that consume atmospheric CO2. This process has often been invoked as a driver of long-term cooling. However, erosion can also expose sulfide minerals. When sulfides oxidize, they produce sulfuric acid. This acid can dissolve carbonate minerals and release CO2 over geological time scales. The net carbon effect of weathering therefore depends on the balance among silicate weathering, carbonate weathering, and sulfide oxidation. However, the responses of different rock weathering processes to changes in erosion rate remain poorly understood.

To address this scientific issue, Dr. Jinke Liu and Prof. Guilin Han from China University of Geosciences (Beijing) conducted a detailed study of the Lancang River basin on the southeastern margin of the Tibetan Plateau. The team integrated river water chemistry, suspended geochemistry, stable isotope data, channel steepness indices, and erosion rate records. They further applied a convex optimization-based inverse mixing model to quantify the contributions of different sources to dissolved solutes in the river.

The results show that dissolved solutes in the Lancang River mainly come from carbonate and evaporite weathering, while sulfate is mainly derived from sulfide oxidation. After the influence of runoff was removed, different weathering processes showed contrasting responses to erosion. As erosion increased, silicate weathering rates decreased, whereas carbonate weathering and sulfide oxidation rates increased.

The study also found evidence for secondary calcite precipitation in river water, based on calcium isotopes in suspended sediment and river water. Changes in the chemical composition of suspended sediment suggest that silicate minerals may continue to dissolve during downstream transport. Lithium isotopes, hydrogen and oxygen isotopes, and water chemistry further indicate that non-geothermal groundwater contributes substantial amounts of dissolved solutes to the river. Together, these processes can modify the link between erosion rate and chemical weathering at the basin scale. They may also help explain why weathering rates respond differently to erosion in different river basins.

On geological time scales, CO2 released by sulfide oxidation coupled to carbonate weathering in the Lancang River basin exceeds the CO2 consumed by silicate weathering. Downstream in the lower Mekong River plain, where erosion rates are lower and lithology changes, the carbon effect of weathering shifts from a CO2 source to a CO2 sink. Comparison of the Lancang River basin with small silicate-dominated catchments in orogenic belts shows that the Lancang River basin has a moderate erosion rate but still acts as a carbon source. The study suggests that this phenomenon is closely related to differences in basin lithology, thereby complementing and deepening previous understanding of the relationship between erosion rate and carbon effects.

The findings provide new geochemical evidence that lithology, suspended sediment weathering, and groundwater input are important controls on chemical weathering and its carbon effect in large river basins. They also refine how scientists evaluate the relationship among tectonic erosion, chemical weathering, and climate change.

Scaling between Ca/Na in suspended load and calcite saturation index (A), riverine Ca and carbonate cation concentrations (B), and Ca lost to precipitation (C). The concentration of Ca lost to precipitation is calculated from the fraction of Ca remaining in the water (β) and riverine Ca concentration.

The circles represent the Lancang River, while diamonds represent small mountain streams. The colored symbols are calculated with runoff correction θsil =0 and θsulf,carb = −0.75 while the gray symbols are calculated without runoff correction. For most data points, the application of runoff correction does not change the qualitative determination of net CO2 source or sink status. The data for the whole Mekong River basin and other mountain rivers are reported in Bufe et al. (2024) and Relph et al. (2021).

Credit

©Science China Press

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Journal

Science China Earth Sciences

DOI

10.1007/s11430-026-2009-5

Method of Research

Observational study

 SPACE/COSMOS

Europlanet Prize for Public Engagement 2026 awarded to CosmoAmautas

Europlanet

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Gabriela Calistro Rivera accepting the Europlanet Prize for Public Engagement 2026 on behalf of CosmoAmautas.

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Credit: Europlanet

The 2026 Europlanet Prize for Public Engagement has been awarded to CosmoAmautas, a Peruvian non-profit association that uses planetary science and astronomy as a gateway to spark curiosity and bring scientific opportunities to children and young students across Peru.

Dr Gabriela Calistro Rivera received the prize on behalf of CosmoAmautas at the recent Europlanet Science Congress (EPSC2026) in The Hague and gave a public lecture about the work of the association. The prize is accompanied by a cash award of 1000 Euros.

Thibaut Roger, presenting the prize on behalf of Europlanet, said: “We are proud to honour CosmoAmautas through the Europlanet Prize for Public Engagement. This dynamic and innovative association has demonstrated how rural schools can be supported to become places where planetary science and astronomy are not only explained, but actively and sustainably practised, for example through the search for exoplanets using real data.”  

Since 2021, CosmoAmautas has trained over 200 teachers across 21 out of 24 regions of Peru, supported more than 80 Astroclubs, and reached over 10,000 students through participating teachers. With a focus on inquiry-based learning, the team of researchers and educators has developed a range of resources, adapted to schools with limited infrastructure and linked to the Peruvian curriculum, that can be delivered to teachers through experiment boxes, printed guides and online materials. Activities covered include measuring the Earth’s rotation and dimensions, investigations with scale models of the Solar System and analysis of space mission data. Gender equality and inclusion are key values of the association and programmes are integrated with Andean ancestral astronomical traditions, showing that observing and interpreting the sky are deeply rooted in Peru’s cultural history.

The CosmoAmautas team is composed of Peruvian students and astronomy professionals living in Peru and all around the globe and working across all fields of astronomy and planetary sciences. In order to reach underserved communities, the initiatives developed by the team have occurred mainly online, but future plans include in-person events that will be partially supported by the Europlanet prize funding. 

On receiving the prize, Gabriela Calistro Rivera said: “It is a great honour to receive the Europlanet Prize for Public Engagement on behalf of CosmoAmautas. ‘Amauta’ means teacher in the quechua language, and our programme is based on the principle that when a teacher is empowered, the future of an entire community can be transformed. This award recognises not only the CosmoAmautas team, but also our community of teachers and students across Peru. This is a great incentive to continue our efforts in bringing scientific education and access to astronomy to more regions and students in our country.”

Gabriela Calistro Rivera, on behalf of CosmoAmautas, accepting the Europlanet Prize for Public Engagement 2026 from Thibaut Roger, Chair of the Europlanet Outreach Working Group.

Credit

Europlanet

 

"Mom says a pink flight jacket is ok"

Women astronauts reframe STEMM, one post at a time. New Paper in JCOM

Sissa Medialab

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Why can’t a flight jacket be pink or purple? That was the question a 6-year-old girl asked her mother, Kellie Gerardi, an astronaut, researcher and science communicator. When Gerardi later appeared on a TV interview wearing a bright pink flight jacket, her daughter pointed to her mom on the TV screen, smiling with delight. This exchange  — which appeared in a post on Gerardi’s Instagram account — was a personal moment, skillfully presented through the language and visuals of social media. But it also conveys a clear message: femininity and scientific credibility are not mutually exclusive.

The video is one of 194 posts analysed in a new study published in the Journal of Science Communication (JCOM), which examined the Instagram activity of three women astronauts and science influencers: Kellie Gerardi, Shawna Pandya and Norah Patten. The research was conducted by Karen Shalev and Shannon Pappas, both graduate students, and Jocelyn Steinke, professor of communication at the University of Connecticut. It shows that science communication on social media involves more than explaining facts and concepts. Personal experiences, the communicator’s identity and platform-specific tools — from music and hashtags to humour and references to popular culture — all contribute to shaping the message.

“Our major finding was that these three science influencers were strategic in the way they framed messages on Instagram, not only to communicate scientific information, and hopefully to foster public interest and engagement in STEMM, but also to build their own personal brands and expand their audiences on Instagram,” Steinke explains.

What to look at, how to interpret it and where to focus

The study examined posts published on the influencers’ three Instagram accounts between 24 June and 24 November 2024, following the announcement of an upcoming Virgin Galactic research mission featuring Gerardi, Pandya, and Patten as an all-women, international crew. The researchers analysed all components of the posts, including photographs, videos, written text, audio, hashtags and emojis.
Their aim was to investigate three aspects of communication: what topics the influencers selected, how they framed them, and which communication tactics they used to attract attention. In other words, the researchers considered what influencers’ encouraged audiences to think about, how they guided audiences to interpret them, and where they directed audiences’ attention.

The analysis identified six broad topics, seven message frames and five types of communication tactics. Some of the topics the women selected focused on their research and training, explained scientific phenomena, and showed experiments conducted in microgravity. At the same time, they shared the personal journeys that had led them to STEMM — science, technology, engineering, mathematics and medicine — and spoke about the people who had encouraged them, the challenges they had faced and aspects of their everyday lives.

Gerardi, for example, has spoken publicly about motherhood, infertility and her experiences with in vitro fertilisation. Patten shared photographs from her first visit to the Kennedy Space Center with her father and brother when she was 15, while Pandya recalled experiences and mentors who contributed to her path to becoming an astronaut. These posts allow audiences to see not only the scientific work, but also the people carrying out this work and the rarely linear paths that brought them there.
“We can see that there’s definitely a strategic attempt here not only to share knowledge about STEMM and STEMM careers, but also to provide that insider perspective and to connect with audiences more personally, trying to foster authenticity, connection and engagement with very broad and diverse audiences,” Steinke says. “By sharing their experiences with their audiences, they can indeed serve as influential role models for future generations and inspire girls to consider potentially being an astronaut in the future.”

Science on in the language of Instagram

The posts analysed in the study adopt the forms and conventions of social media: short videos, photo carousels, text overlaid on images, hashtags, emojis, trending music and references to popular culture.

Taylor Swift, David Bowie and Charli xcx all are featured in some of the posts. Gerardi jokingly refers to herself as a “bratstronaut,” while footage of parabolic flights is accompanied by songs about space or weightlessness. The women also use humour, wordplay and immediately recognisable visual elements, including flight suits, models, clothes decorated with stars and planets, and footage recorded during training.

According to the authors, these elements are more than decorative additions. They help adapt the content to the platform, attract attention and connect science with forms of expression that are already familiar to Instagram users.

The personal dimension can also help challenge traditional ideas about the people who work in science. In their posts, the three women present themselves simultaneously as astronauts, researchers, doctors, mothers, daughters and women interested in fashion or music. By making these different identities visible, they show that there is no single way to look or behave in order to be credible in STEMM. 

Useful insights

This is a qualitative analysis of messages shared by three highly visible STEMM figures on a single platform and over a limited period.The study did not establish whether every communication choice was consciously planned by the women, nor whether they manage their accounts with professional assistance. It also did not examine how audiences interpreted the posts or which content attracted the most attention and engagement.

Although future research should address these important issues, the influencers’ combined following of more than 1.5 million Instagram users at the time the study was conducted, highlights the potential reach of their content. The study findings about the science communication practices of three popular science influencers on Instagram also offer useful insights for the training of scientists and science communicators. Communicating strategically means considering not only what information to convey, but also how to present it, which parts of one’s experience to share, and how to adapt a message to the context in which audiences will encounter it.
“Women in STEMM are using social media as a way of gaining visibility and voice, advancing their goals as science communicators, changing perspectives on the role and contributions of women in STEMM, and inspiring younger generations to consider STEMM careers as a future option,” Steinke concludes.
 

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Journal

Journal of Science Communication

DOI

10.22323/373620260614012713

Method of Research

Case study

Article Title

Framing science on social media: strategic science communication practices of women astronaut science influencers on Instagram

Article Publication Date

1-Oct-2026

Life on Saturn’s moon would be possible

Ludwig-Maximilians-Universität München

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The microorganism Methanothermococcus okinawensis, whose ability to survive on Saturn's moon Enceladus the researchers have tested.

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Credit: Chiara Morawetz & Reinhard Rachel (University of Regensburg)

Saturn’s icy moon Enceladus might be more supportive of life than was previously thought. An LMU study reveals that microorganisms could survive in its hidden ocean.

From a human perspective, Enceladus is anything but a comfortable place to live: Icy cold, hardly any oxygen, and – below its icy crust - a global subsurface ocean whose water is as corrosive as pipe cleaner. Despite this, Saturn’s moon is one of the few places in our solar system where the conditions for life to emerge could be present. A new study supervised by William Orsi, who is Professor of Geomicrobiology at LMU, now presents experiments showing in specific detail that certain microorganisms could survive there and how they are able to do so.

Orsi’s team recreated the conditions thought to exist on the seafloor of Enceladus in the laboratory and discovered that hydrogen-consuming, methane-producing archaea seem to be able to adapt to this environment previously considered to be deadly for anaerobe archaea.

This evidence could only be produced thanks to collaboration between different disciplines, including geomicrobiology, biochemistry, geochemistry, and planetary science. The study, which involved scientists from LMU as well as the Woods Hole Oceanographic Institution, the University of Regensburg, and Freie Universität Berlin, was recently published in the science journal Science Advances.

“Enceladus is considered to be one of the most promising places to search for extraterrestrial life,” says Dr. Vanessa Helmbrecht, lead author of the study. “Our experiments show that its unique geochemistry could create conditions that are even more favorable for microbial life than we had previously thought.”

Simulating an extraterrestrial ocean floor

Beneath Enceladus’ thick ice shell lies an ocean of liquid water and a solid core. Data from NASA’s Cassini mission revealed that the moon’s water-rich plumes that regularly shoot up from the ice contain molecular hydrogen, methane, and dissolved minerals – this provides strong evidence of hydrothermal activity on the seabed, and water-rock geochemical reactions, where the rocky core meets the ocean.

The researchers used a special anoxic chamber to create similar deep-sea conditions with a very low level of oxygen– a kind of “Enceladus simulant.” The oxygen concentration was extremely low – roughly 10,000 times lower than the level of oxygen in the Earth’s atmosphere. Under these conditions, the researchers used carbonate salts to simulate a hypersaline liquid that replicated both the moon’s alkaline soda ocean and its rocky ocean floor.

They then introduced Methanothermococcus okinawensis, a methane-producing archaeon that normally lives near deep-sea hydrothermal vents on Earth.  The metabolic pathway used to by this organism to conserve energy requires only H2 and CO2 gases, and is considered to be one of the most ancestral metabolisms still retained by life on Earth today.

The results were striking: While the organism failed to grow in a conventional laboratory medium at a pH of 10 or 11, in the Enceladus simulant it continued to grow, producing methane using hydrogen generated by water-rock reactions.

How microbes overcome carbon scarcity

One of the biggest challenges for life to potentially exist on Enceladus is the extremely low concentration of carbon dioxide caused by the ocean’s high pH. The team was able to demonstrate that Methanothermococcus okinawensis could adjust to these conditions and use its unique metabolism to scavenge the tiny amounts of available CO₂ to continue growing.

“Our findings suggest that the chemistry of Enceladus itself can help overcome this major barrier to life,” says William Orsi. “The interaction between the rock and water not only produces hydrogen as a source of energy, but also creates conditions that allow microbes to keep accessing carbon, even though CO₂ is extremely scarce.”

Broader implications for the search for life in space

The findings expand the range of conditions under which scientists consider Enceladus to be potentially able to sustain life.

“Our study doesn’t prove that life exists on Enceladus,” says Orsi,“ but it does show that key geochemical features of its environment can support one of life’s most ancient metabolisms. This strengthens the scientific case for future missions to retrieve samples from the moon’s ocean-derived plumes.”

ESA has recently announced plans to do exactly that with its next major flagship space mission “L4”, currently foreseen to launch in 2042.

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Journal

Science Advances

DOI

10.1126/sciadv.aei0167

Article Title

Enceladus-like geochemistry fuels methanogenesis under extreme CO2 limitation

Article Publication Date

25-Oct-2026

The microorganism Methanothermococcus okinawensis, whose ability to survive on Saturn's moon Enceladus the researchers have tested

The microorganism Methanothermococcus okinawensis, whose ability to survive on Saturn's moon Enceladus the researchers have tested.

Credit

Copyright: Chiara Morawetz & Reinhard Rachel (University of Regensburg)

Following ancient rain toward the origins of life on Mars

Ancient rain on Mars may have left a trail of formaldehyde across the planet. Following it could help future missions identify where to search for clues to the origins of life there

Tohoku University

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Modeled global distribution of annual atmospheric formaldehyde (H₂CO) delivery to the surface of early Mars, overlaid on present-day topography with rover landing sites. Darker colors indicate higher delivery.

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Credit: Shungo Koyama et al.

The Mars we know today is a cold, dry world of dust and rocks. However, around 3.8-3.6 billion years ago, it may have looked very different. Geological and mineral evidence suggests that, in its distant past, the planet experienced periods warm and wet enough for water to exist on its surface, potentially forming rivers, lakes, and even an ocean in the northern hemisphere.

Earlier research has also shown that formaldehyde (H₂CO) could have been produced in the atmosphere of warm early Mars. The importance of this substance is that once delivered to water, formaldehyde can serve as a starting material for chemical reactions that produce sugars, amino acids, and other complex organic molecules - compounds important to ultimately start life. Yet one major question remained unanswered: where on Mars would this formaldehyde have actually reached the surface?

To answer this question, a research team led by scientists from Tohoku University, the Earth-Life Science Institute, and the Institute of Science Tokyo created a global map showing where atmospheric H₂CO may have been delivered across the planet during its early history.

To build this visualization, the researchers simulated warm conditions around 3.8-3.6 billion years ago and examined how temperature, water vapor, pressure, and UV light affected the formation of H₂CO. Their research showed that water vapor was especially important for Martian formaldehyde production. UV light broke apart water molecules, releasing reactive hydrogen needed to form H₂CO in the atmosphere, while rainfall carried the formaldehyde down to the surface. As a result, water-rich regions were predicted to receive more formaldehyde than drier areas.

Because water influenced both the formation of H₂CO and its delivery to the surface, the researchers suggest that the Martian water cycle may have determined where this prebiotic molecule could accumulate. The map they created shows where these predicted hotspots lie in relation to the landing sites of Mars missions.

"By comparing our map with findings from rovers, we can begin to test whether places that received more H₂CO were also more favorable for early life-related chemistry," said Dr. Koyama. "If future observations confirm this relationship, our map could help identify promising targets for future Mars missions."

Some areas of Mars stood out clearly on the map. For example, the model predicted that mountainous regions such as Tharsis and Elysium received about ten times more H₂CO than the global average. However, these estimates show how much H₂CO may have reached the surface in the past, not how much remains there today.

This study may provide guidance toward potential landing sites for future Mars missions, which may help us better understand how organic chemistry developed on the planet billions of years ago, bringing us one step closer to unraveling the mysteries surrounding the origins of life there.

The findings were published in The Planetary Science Journal on September 30, 2026.

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Journal

The Planetary Science Journal

DOI

10.3847/PSJ/ae9942

Article Title

Global distribution of atmospheric formaldehyde deposition correlated with water vapor on a warm early Mars

New study rekindles contested question: Earth and Mars had different origins

University of Copenhagen

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Four and a half billion years ago, Earth and Mars were born in the rotating cloud of gas and dust that would eventually become our Solar System.

Yet exactly how the planets formed remains one of the most disputed questions in planetary science.

Now, researchers at the University of Copenhagen are adding new evidence to the debate. Using a novel approach, they have reconstructed the earliest stages of the planets’ formation by analysing their chemical composition.

And the results surprised them.

“The most surprising result was that Earth and Mars appear to have formed in different ways. You might have expected that two planets formed side by side in the same solar system would share a more similar formation history,” says Professor Anders Johansen, who studies planet formation at the Globe Institute, University of Copenhagen. He co-led the new study with Assistant Professor Haiyang Wang.

The birth of Mars and Earth

Today, researchers broadly agree that planets are formed primarily in one of two ways, or through a hybrid of both processes:

Planets either emerge when giant space rocks, known as planetesimals, collide, or when these large rocks accumulate smaller particles, a process known as pebble accretion.

Planetary scientists have not settled on which of the two processes or a combination thereof would best explain how rocky planets such as Earth and Mars formed.

The researchers behind the new study believe that their findings support the so-called hybrid model. However, the study takes one step further and offers a more explicit explanation of how Earth and Mars formed 4.5 billion years ago.

“At least 75 percent of Earth’s mass appears to originate from two young planets, known as protoplanets, that grew large by accreting pebbles, while planetesimals contributed up to 25 percent. In contrast, roughly three-quarters of Mars’ mass appears to come from planetesimals, with the remaining quarter originating from pebble accretion,” says Haiyang Wang.

Planetary chemistry reveals the past

To understand how planets formed billions of years ago, scientists must rely on traces that still exist today.

In the new study, the researchers closely examined specific elements in the outer layers of the planets: the crust and mantle. They focused particularly on so-called volatile elements, which evaporate relatively easily at high temperatures, such as sodium, zinc, and potassium.

According to the researchers, the presence, or absence, of these elements acts as a chemical fingerprint that reveals the processes planets underwent during their formation. Using advanced computer models, they can then determine which formation scenarios are the most likely explanations for the origins of Earth and Mars.

“It is a major detective job to figure out what happened back then when most of the evidence disappeared long ago. But even after 4.5 billion years, the compositions of Earth’s and Mars’ mantles remain the same. You can think of them as an imprint of the formation process,” says Anders Johansen.

The researchers emphasize that their computer models contain uncertainties. For example, the exact chemical composition of the original building blocks in our Solar System that eventually became Earth and Mars remains unknown.

As a result, the models rely on several assumptions. However, even when adjusting for those assumptions, the main conclusion remains unchanged.

“The exact percentages may vary somewhat, but our analyses consistently indicate that Earth and Mars formed in two different ways. Our method provides a more precise and direct way of understanding planet formation than the more widely used isotope-based approach, which can often be interpreted in multiple ways,” says Haiyang Wang.

Could help the search for habitable planets

The researchers also see applications beyond our own Solar System.

Several future space missions aim to discover and study Earth-like planets in other galaxies.

Understanding the chemical compositions of such planets is important for assessing whether they are potentially habitable, the researchers point out.

“If we understand how planets lose volatile elements during their formation, we can also become better at predicting how much water and other life-supporting substances they ultimately retain,” says Anders Johansen.

 

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About the study

• The study investigates how Earth and Mars formed 4.5 billion years ago by analysing specific elements in the crust and mantle of the two planets. The researchers used advanced statistical computer modeling to calculate the most likely formation processes.

• According to the study, Earth and Mars formed in different ways: Mars formed primarily through collisions between massive rocks known as planetesimals. Earth, by contrast, began largely as two protoplanets that grew by gathering pebble-sized particles in a process called pebble accretion.

• The findings support the so-called hybrid model, in which both mechanisms contributed to planetary formation.

• The researchers stress that the results are based on statistical modeling and a number of assumptions regarding the composition of the building blocks present in the young Solar System that later would become the two planets. These include the assumption that the planetesimal building blocks of Earth and Mars were chemically similar to the asteroid Vesta, and that volatile elements are lost more efficiently during pebble accretion than during giant impacts.

• The researchers used computer simulations to demonstrate that volatile elements are lost from pebbles as they travel toward a planet’s surface.

• The study was published in the scientific journal Nature Astronomy.

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Journal

Nature Astronomy

DOI

10.1038/s41550-026-02984-6

Article Title

Volatile depletion in rocky planets as a chemical fingerprint of hybrid accretion

Astronomers link mysterious cosmic flashes to collisions of dead stars

Observations led by a graduate student and his colleagues helped connect an X-ray flash lasting nearly ten minutes to a merger of neutron stars.

ERC BHianca

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The bright glow of EP250704a is marked by white lines in this false-colour image (optical: blue/green; near-infrared: red) from ESO’s Very Large Telescope (top panel). Its spectrum, recorded with the X-shooter instrument (bottom panel), shows absorption features associated with iron (purple) and magnesium (red). The positions of these features revealed a redshift of 0.6610, establishing the explosion’s distance from Earth. These observations provided a crucial clue that helped connect the nearly ten-minute X-ray flash to a merger of neutron stars.

 

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Credit: Niccolò Passaleva, Eleonora Troja (ERC BHianca), ESO/VLT

For decades, astronomers have identified the collisions of two neutron stars through bursts of gamma rays that can disappear in less than two seconds. But some of these violent encounters may also reveal themselves through X-ray flashes lasting several minutes. A new study published in Science Bulletin provides compelling evidence for this connection, suggesting that merging neutron stars could be hiding among cosmic flashes whose origins have remained uncertain.

Since the launch of the Einstein Probe satellite in January 2024, astronomers have been discovering hundreds of bright flashes of X-rays from distant galaxies. Known as fast X-ray transients, some of these flashes have been linked to the deaths of massive stars, but others remain unexplained. Without knowing their distance and the energy they release, astronomers struggle to determine what produced them.

Researchers in Professor Eleonora Troja’s group, supported by a European Research Council (ERC) Consolidator grant, obtained observations crucial to identifying the source of one such X-ray transient. Following an alert from the Einstein Probe satellite, the team quickly arranged observations with other telescopes, including the European Southern Observatory’s Very Large Telescope (VLT) and the Very Large Array, to study the explosion’s aftermath. They believe to have witnessed the birth of a magnetar produced by the collision (or merger) of two neutron stars. 

An X-ray flash with a record-setting duration

Neutron stars are the ultra-dense stellar corpses left behind when massive stars reach the end of their lives. When two neutron stars collide, they send gravitational waves rippling through space. The light from these events offers a glimpse of what the collision leaves behind. 

Gamma-ray bursts of short duration have long been the main signpost for these events. “However, if the remnant of the collision is a magnetar, it could keep bursting for longer” said Prof. Troja, who is part of the Einstein Probe European collaboration and co-corresponding author of the paper. “Magnetars are rapidly spinning neutron stars with huge magnetic fields. When they damp their magnetic power into the surroundings, they can make any explosion brighter and longer-lasting. When I saw the X-ray data from this new event, I realized something was up.” 

The event, known as EP250704a/GRB 250704B, was discovered on 4 July 2025 by the SVOM, Insight-HXMT and Einstein Probe satellites. Its blast of gamma-rays lasted about half a second, while the Einstein Probe satellite recorded bright X-ray radiation for nearly ten minutes.  “This is the longest lasting prompt X-ray flash ever observed from a neutron star merger,” said graduate student Niccolò Passaleva, who led the follow-up observations using the VLT in Chile. “It is an opportunity to have a front-row seat to the most extreme forces of the Universe and discover more of its secrets.”

A new window on stellar collisions

The team had been searching for a connection between fast X-ray transients and neutron star mergers for several years, but earlier candidates faded away before providing a decisive answer. This time, Passaleva reacted within minutes and began observing while the light from the explosion was still bright enough to study in detail. “I was traveling home by train,” recalls Passaleva, “and all of a sudden I was rushing against time to commandeer one of the largest telescopes in the world from my laptop.” 

Using the VLT’s X-Shooter instrument, Passaleva and his colleagues separated the light into its components and identified clear absorption patterns, whose position revealed the burst’s distance from Earth, known as redshift. The measured redshift of z=0.6610 revealed that the explosion had occurred long before our Sun and its planets formed, and the burst's light had travelled for more than six billion years before reaching us.

The team then used deep images from the VLT’s FORS2 instrument to search for a bright supernova, the exploding star expected to accompany a long-lasting X-ray flash caused by the collapse of a massive star. None appeared. The distance measurement, the absence of a supernova and the properties of the burst together provided strong evidence for a neutron star merger.

“Finding more of these X-ray flashes could help reveal how often neutron star mergers create magnetars,” concludes Passaleva, “I am really excited for the next run of gravitational wave observations, when we could finally pair one of these X-ray flashes with a burst of gravitational waves from the same source.”

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Additional Information

The research was carried out by an international collaboration of astronomers. Lead authors are: An Li (Beijing Normal University), Chen-Wei Wang (Chinese Academy of Sciences), Niccolò Passaleva (University of Rome Tor Vergata), Jie An (Chinese Academy of Sciences) 

Corresponding authors are:  Binbin Zhang (Nanjing University), Eleonora Troja (University of  Rome Tor Vergata), Yi-Han Iris Yin (The University of Hong Kong), Jing-Wei Hu (Chinese Academy of Sciences), Hua-Li Li (Chinese Academy of Sciences)

The VLT observations used in this study were conducted as part of the large program 114.27LW (PI: Eleonora Troja) titled “QUEENB: a QUEst for Elusive Neutron star and Black hole mergers”

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Journal

Science Bulletin

DOI

10.1016/j.scib.2026.08.021

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Minutes-long soft X-ray prompt emission from a compact object merger

Article Publication Date

30-Sep-2026

Study links 90+-day spaceflights to higher rates of hip fractures in astronauts

Findings in Mayo Clinic Proceedings open up a new area of research to safeguard astronauts’ skeletal health ahead of planned long-duration space missions

Elsevier

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A study in Mayo Clinic Proceedings has found that astronauts who have been in space for more than 90 days had a higher rate of hip fractures when they returned to Earth compared to astronauts on shorter spaceflights and non-astronauts. The findings underscore the need for expanded assessment of long-term skeletal health in astronauts. This figure shows the classification of fracture counts and events. NSF = No-Spaceflight, NLD-SF = Non-Long-Duration Spaceflight, LD-SF = Long-Duration Spaceflight.

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Credit: Mayo Clinic Proceedings / Taylor et al.

October 1, 2026 – New research has found that the rate of hip fractures in astronauts back on Earth was greater in the time period after an astronaut has been in space for more than 90 days than in the time period following shorter spaceflights or in non-astronauts. The findings of the study in Mayo Clinic Proceedings, published by Elsevier, underscore the need for expanded assessment of long-term skeletal health in astronauts.

The National Aeronautics and Space Administration (NASA) is planning multiple missions with durations of longer than six months in space, including commercial low Earth orbit activity, completing Artemis IV’s first human mission to the lunar south pole in 2028, and enabling sustainable surface capabilities for the moon in preparation for Mars. Increased human participation and time spent in extraterrestrial exploration could negatively affect the long-term skeletal health of astronauts selected for their physical fitness and optimal health.

Muscle and bone loss due to the microgravity environment of space is a common physiologic phenomenon among astronauts that suggests a risk for fragility due to an adaptive response to disuse.

Jean D. Sibonga, PhD, lead investigator of the study “Increased Rates of Hip Fractures Associated With Longer Spaceflight Durations” at NASA’s Johnson Space Center, noted that humans do not feel the effects of bone loss. After returning from space and feeling stable or recovered, they may resume physically demanding activities despite underlying skeletal changes caused by prolonged disuse. A better understanding of bone health after spaceflight could help astronauts, patients, and clinicians assess long-term health concerns, determine appropriate care, and reduce the risk of injury.

Co-author of the accompanying editorial “Bone Loss in Astronauts” Matthew T. Drake, MD, PhD, Endocrinology and Metabolic Bone Disease Service, Hospital for Special Surgery, New York, notes, “While data to date on bone loss associated with space flight are consistent, a major limitation is accuracy, as astronaut cohort sample sizes are small and spaceflights are rare.”

To overcome this statistical limitation, investigators surveyed a cohort of US-based astronauts for all fractures reported during annual clinical exams and analyzed these data using Bayesian probabilistic modeling. While they did not find a higher incidence rate for all fractures, the incidence rate for hip fractures in astronauts was increased after a long-duration spaceflight of more than 90 days.

This increased rate occurred at a younger age than would be expected in a non-astronaut terrestrial population, and at a greater hip fracture rate than the rate before a long-duration mission, or with no spaceflight exposure at all.

“Taken together, the finding of hip fracture occurrence at an age earlier than expected after long-duration spaceflight is clinical evidence that spaceflight-induced bone loss can lead to real long-term fracture consequences, which should be addressed accordingly,” says Moshe Gertzulin, MD, Endocrinology and Metabolic Bone Disease Service, Hospital for Special Surgery, New York, co-author of the accompanying editorial.

Dr. Sibonga emphasized the need to expand NASA’s current bone surveillance program beyond dual-energy X-ray absorptiometry measurements of bone mineral density to better evaluate astronauts’ long-term fracture risk. NASA has recently begun ordering quantitative computed tomography scans before and after spaceflight, which can provide more detailed information about different areas of the bone and whether astronauts have fully recovered. Without that insight, astronauts could risk placing too much strain on bones that have not yet regained their preflight condition.

To mitigate these risks, the investigators advocate for prophylactic countermeasures that would preserve the baseline, pre-flight skeletal health of the astronaut. A fuller characterization of spaceflight-induced changes to bone mass, density, structure, and microarchitecture will determine which interventions—whether drugs, exercise, or dietary adjustments—are most beneficial for long-term skeletal health in astronauts.

 

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Journal

Mayo Clinic Proceedings

DOI

10.1016/j.mayocp.2026.06.025

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Increased Rates of Hip Fractures Associated With Longer Spaceflight Durations

Article Publication Date

1-Oct-2026